Aircraft structure testing device of the wire cutter type

Abstract

A detection wire cutter including a conducting wire mechanically secured to a structure that is to be monitored. This wire is electrically powered at one end and at another end feeds back an electrical voltage corresponding to the power supplied, provided that the structure that is to be monitored has not undergone unacceptable mechanical damage. As an improvement, two arrays of wires extending over flat supports in two directions in space are proposed. Each array is powered by a distinct network electrical supply. The two networks extend in layers, with parallel wire portions. The position of a crack does not impede the passage of current between certain terminals, but certain other terminals will no longer receive any current because the crack has broken a network supply general connection between the connection of one wire and that of another.

The invention claimed is: 
     
       1. Aircraft structure testing device of the wire cutter type, comprising:
 a conducting wire mechanically secured to a structure to be monitored, and connected at one end to an electrical supply and outputting at another end an electrical current and/or voltage corresponding to the supply, if no crack exists in the structure of said aircraft to be monitored, 
 two independent wire arrays extending on flat supports in two spatial directions, 
 the supports being secured to the structure, 
 each array being connected to a distinct electrical array supply, 
 all the wires of a wire array being connected to the electrical array supply of the array they belong to, 
 both arrays extending in layers, with portions of wires being arranged in a parallel configuration, and 
 portions of wires of one array being oriented in a direction perpendicular to that of the portions of the other array. 
 
     
     
       2. Device according to  claim 1 , further comprising:
 a microprocessor and a program memory for putting into service, successively in time, each of the electrical supplies and for measuring electrical signals output by the array in service. 
 
     
     
       3. Device according to  claim 2 , wherein
 the microprocessor and the program memory which measure, successively in time, electrical potentials and/or currents output by each of the conducting wires in service. 
 
     
     
       4. Device according to  claim 3 , further comprising:
 a decoder controlled by the microprocessor. 
 
     
     
       5. Device according to  claim 4 , further comprising:
 a parallel connection of the conducting wires of an array and 
 in the program and the microprocessor, a function for measuring the equivalent resistance, in order to deduce the damage position. 
 
     
     
       6. Device according to  claim 5 , further comprising:
 a layer of polytetrafluorethylene, one face of which is metallized and which is cut with a definition corresponding to that of an array of wire portions. 
 
     
     
       7. Device according to  claim 6 , further comprising:
 for an array, a unique support cut into thin strips. 
 
     
     
       8. Device according to  claim 7 , wherein
 both arrays form a matrix pattern. 
 
     
     
       9. Device according to  claim 8 , wherein
 both arrays form a comb-shaped pattern. 
 
     
     
       10. Device according to  claim 9 , wherein both arrays are interconnected together.